Keba
Austrian precision EV chargers with Modbus UDP local API — the engineer's choice for KNX load management.
Keba (Linz, Austria — founded 1968) manufactures industrial automation equipment and EV charging stations. Their KeContact series (P20, P30, KC-P30) is among the most specification-grade EV chargers available in Europe — used in residential, fleet, commercial parking and public charging applications. Keba chargers are distinguished by their local UDP API (no cloud required for control), full Modbus TCP support, OCPP 1.6 compliance, and the ability to reduce charging current to any value between 6A and 32A in 1A steps. This makes them ideal for KNX dynamic load management projects via Home Assistant or a dedicated Modbus gateway.
Role in our panels
How we use Keba
Keba KeContact integrates with KNX in two primary ways: (1) KNX relay output → charger enable/disable (on/off only), or (2) full dynamic current control via Modbus TCP or UDP local API through a Home Assistant bridge. The Keba UDP API (port 7090) provides real-time status and current setpoint commands with ~100ms latency — faster than cloud-dependent solutions. The Modbus TCP interface (port 502) is standard for DIN-rail mounted Keba units (KC-P30 series) used in apartment block and commercial installations. Combined with a Modbus energy meter on the main supply, the complete system achieves true dynamic load management: main current read every 10s → available EV budget calculated → Modbus write to Keba current register. KNX group addresses control charging modes (off, eco, boost, solar) via Home Assistant automations.
In KNX panel design, Keba integration is planned at the panel level even though the KNX-Keba interface is software (HA or Modbus gateway). Key panel requirements: (1) Separate MCB and RCD Type B (or A with DC detection) for each Keba charger circuit; (2) KNX 230V binary output relay for simple enable/disable fallback; (3) Modbus gateway (MDT, Weinzierl or Intesis) or HA Raspberry Pi for dynamic current control; (4) Current transformer (CT) on main supply for load monitoring — Keba does not include a CT clamp, unlike Easee Equalizer; (5) For KC-P30 DIN-rail units: RS-485 RTU bus or Modbus TCP over Ethernet runs to panel patch. The KNX integration path: KNX scene group address → HA automation → Keba UDP API call (setcurr command) or Modbus write to register 5004.
Used in these project types
Keba products
Key components we install
Keba KeContact P30 a-Series
Residential and light commercial wall-box, 11kW or 22kW (Type 2), IP54. Built-in MID energy meter (legal metering for billing). Ethernet + Wi-Fi. UDP local API + OCPP 1.6. The most common Keba unit in European residential KNX projects. Available in multiple colors and bezels.
Keba KeContact P30 c-Series
Commercial grade, 22kW, RFID reader, MID energy meter, dual socket option. Designed for office parking, hotel car parks and apartment blocks with billing requirements. OCPP 1.6 + Modbus TCP. Supports multiple RFID authorization profiles.
Keba KC-P30
DIN-rail mounted charging controller (no enclosure) — installs inside a distribution panel. For trunking installations in apartment parking or underground car parks where a wall-mounted box is not practical. Modbus RTU RS-485 interface. Pairs with separate Type 2 socket and cable management.
Keba KeContact P20
Simplified residential charger, 11kW, no MID meter, basic Ethernet. UDP API for current control. Cost-effective option for single-family residential where billing is not required and KNX solar surplus dispatch is the primary use case.
Keba FAQ
How does Keba's UDP API work for KNX integration?
Keba P30 listens on UDP port 7090. Commands are JSON strings sent as UDP datagrams: to set charging current to 10A, send '{"setenergy": 0}' to start a session, then '{"setcurr": 10000}' (current in mA). The charger replies with status JSON. Home Assistant's Keba integration handles this automatically. For KNX integration, HA receives a KNX telegram on a group address (e.g., 7/0/20 = value 10) and translates it to the UDP setenergy/setcurr command.
Does Keba support load management without external hardware?
Unlike Easee (which includes the Equalizer CT clamp), Keba does not include a supply current monitoring device. For load management, you must add a Modbus energy meter (Eastron SDM, Schneider iEM) on the main supply. The energy meter reads main current → Home Assistant calculates available EV budget → HA sends UDP/Modbus current command to Keba. Keba does support backend OCPP load management if you run a local OCPP server (e.g., EVCC).
Can multiple Keba chargers share a single supply?
Yes — via OCPP Smart Charging or via a central Modbus/UDP controller (HA or Node-RED). Each Keba is addressed by its IP. The control system reads the main supply current, calculates individual allocations, and sends UDP/Modbus commands to each Keba. For simplicity, Keba also supports a master-satellite RS-485 configuration in KC-P30 installations — one Keba reads the CT clamp and distributes current to others on the bus.
What RCD type is required for a Keba charger?
Keba P30 and KC-P30 include an internal DC 6mA fault detection — this satisfies the IEC 62955 requirement, allowing use of a Type A RCD upstream (rather than the more expensive Type B). Always verify with the specific Keba product datasheet and local electrical regulations, as some countries (Germany, Austria) require Type B regardless. PanelCraft pre-wires the correct RCD type based on the project's country of installation.
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